Here's a picture I have found on flickr, taken in an outdoor museum in South Korea. I can only recognize the 1st, 3rd and 4th characters: 寶X山房. 寶 is probably not the variant written on the wooden board, but it's the same character. What is the 2nd character?
The original high resolution image is here.
EDIT: My best guess is 丁, but why this odd curvy shape when the rest of the characters are rendered fairly standard?